SWATH just curious did Mikini replace your main board or spindle board to make the dipping go away? Might try just inspecting your main board solder joints with a magnifying glass that's all I did. I will say the soldering on these boards was not very good there was solder between chip leads as well as on them. Not enough to touch leads but just a messy job. Looks to me like the manufacturer Mikini chose for the electronics job is not the best. Wonder how much they saved over a more reliable manufacturer.
The main board on the LCD panel the one everything plugs in to. That was the one I inspected for bad solder joints.
After getting my tested and certified board wrapped in plastic and Styrofoam balls (static and more static) I recommended to Phil to use anti-static bags for shipping, said they are thinking about it.
When Mikini sent me the version 2 electronics they had thrown it all in a single box with not nearly enough packing material to protect anything. The computer got crushed, and one of the capacitors on the spindle board was pretty munged too. They just threw a bunch of parts in a box and shipped it including a quite heavy BLDC motor to rattle around. I was dumbfounded.
They also told me to send in ALL of my version 1 electronics for the swap and so that is what I did including my smooth stepper. They never returned the smooth stepper. I asked about it and they said no smooth steppers here on the bench sorry.
I could go on and on.